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Parallel? Series? LED driver circuit selection

Parallel? Series? LED driver circuit selection

2017-01-18

LED era, we in all aspects of life are visible in its presence, whether it is a car field, intelligence or industrial fields, because of its high efficiency, energy saving, long life, environmental protection and other features, the optional scheme has now lighting technology, and has been applied in lighting. One of the key factors that drive people to pay attention to LED lighting technology is that it greatly reduces the energy consumption and can achieve long-term and reliable work. Today, we will give you a practical extension of the LED circuit from the introduction of LED lighting drive circuit.
This paper first from the circuit with constant current source, the main components of the circuit in the triode tube, the pressure should be more than 400V, the power to power than 10W, such as MJE13003, MJE13005 etc., and to add heat sink, filter capacitor C capacity of 4.7uF, the pressure to 400V above, light the tube current is decided by the size of R2 adjustment, convenient adjustment available variable resistor adjusted fixed resistor to replace the same resistance, the circuit can be led with few dozen, up to more than and 90, although the increase in cost, but the use effect compared with current limiting resistance circuit is much better and even if the voltage fluctuations, the circuit can still maintain the current constant, which is favorable to the luminous tube life, current within this range can be substantially constant. The use of this circuit can not be too small, the less its efficiency is lower. The total power consumption of the circuit is about 6W.
Circuit of constant current source
Here to tell you about the use of LED parallel connection or series connection good?
The LED shall be connected in series or in series, and should be determined in accordance with the form and requirements of the power supply circuit.
Using the series connection circuit, when one of the LED open circuit when the whole string of LED is not bright; but when one of the LED short circuit when other LED can also be bright. The parallel connection circuit, when one of the LED circuit when other LED are still bright; but when one of the LED short circuit power supply of the whole circuit will be short, so that not only the other LED are not working properly, but also may damage the power supply. Therefore, compared with the series connection circuit has advantages.
Parallel connection requires only a low voltage at each end of the LED, but it is necessary to use the ballast resistor or current source to ensure the brightness of each LED. If the magnitude of the bias current flowing through each LED is different, their brightness is different, which leads to the uneven brightness of the whole light source. However, the use of ballast resistance or current source to ensure that the brightness of the LED will shorten the battery life. The series connection method can ensure the consistency of the current flowing through each LED, but the power supply voltage is high. LED parallel connection method, because the total current of the circuit is the sum of the LED current, so the power supply should be able to supply a large enough current.